Elastic joint for a wheel suspension of a motor vehicle

Abstract

An elastic joint, in particular for a wheel suspension of a motor vehicle. The joint includes an inner armature, an outer armature surrounding the inner armature, wherein the armatures define an axial direction and two radial directions perpendicular to the axial direction as well as perpendicular to each other and disposed in a circumferential plane, and an elastomeric body for the mutual elastic retention of the armatures, wherein the elastomeric body consists of at least four connecting columns respectively extending from the inner armature to the outer armature.

What is claimed is: 
     
       1. An elastic joint for a wheel suspension of a motor vehicle, comprising:
 an inner armature; 
 an outer armature surrounding the inner armature, wherein the armatures define an axial direction and two radial directions perpendicular to the axial direction as well as perpendicular to each other and disposed in a circumferential plane; and 
 an elastomeric body comprising a first portion vulcanized to the inner armature and a second portion fixed to the outer armature for the mutual elastic retention of the inner armature and the outer armature, wherein the elastomeric body includes at least four connecting columns respectively extending from the inner armature to the outer armature wherein the at least four connecting columns are elastically deformable in the radial direction to elastically connect the inner armature to the outer armature and are spaced from one another along the elastomeric body such that the deformation of one of the at least four connecting columns does not affect the deformation behavior of any other one of the at least four connecting columns and wherein the at least four connecting columns are allocated to each other as pairs and one pair of the pairs of connecting columns is arranged circumferentially offset with respect to another pair of the pairs of connecting columns wherein the one pair of the pairs of connecting columns is disposed on one side of a central radial plane of the joint and the another pair of the pairs of connecting columns is disposed on the opposite side of the central radial plane. 
 
     
     
       2. The elastic joint according to  claim 1  wherein the elastomeric body is made from one piece of elastomeric material. 
     
     
       3. The elastic joint according to  claim 2 , wherein each of the at least four connecting columns comprise column bodies that extend rectilinearly. 
     
     
       4. The elastic joint according to  claim 3 , wherein the at least four connecting columns are arranged without contact along their respective column bodies in a respective extension direction. 
     
     
       5. The elastic joint according to  claim 1 , wherein the pairs of connecting columns are arranged axially symmetrically with respect to the axial direction. 
     
     
       6. The elastic joint of  claim 5 , wherein offset angles between neighboring pairs of connecting columns are essentially equal. 
     
     
       7. The elastic joint of  claim 6 , wherein the offset angles are about 90 degrees. 
     
     
       8. The elastic joint according to  claim 1 , wherein the at least four connecting columns each respectively define an extension direction that is inclined with respect to a corresponding radial direction and the directional component of which in the corresponding radial direction is larger than in the axial direction, wherein angles of inclination of the extension direction of each of the at least four connecting columns are of equal size, such that a stiffness of the elastic joint in the axial direction increases when the elastomeric body, which elastically deforms under a load acting in the corresponding radial direction, enables a relative movement between the inner armature and the outer armature in the first radial direction. 
     
     
       9. The elastic joint according to  claim 1 , wherein the at least four connecting columns comprise column bodies, wherein the at least four connecting columns each respectively define an extension direction that is inclined with respect to a corresponding radial direction and the directional component of which in the corresponding radial direction is larger than in the axial direction, wherein the geometries, including contours of the column bodies of the at least four connecting columns, angles of inclination of the extension directions, or a combination thereof are configured such that the elastomeric body, which elastically deforms under a load acting in the corresponding radial direction, enables a relative movement between the inner armature and the outer armature in the corresponding radial direction, without a relative displacement of the armatures in the axial direction. 
     
     
       10. The elastic joint according to  claim 1 , wherein the at least four connecting columns comprise column bodies, wherein a first two connecting columns of the at least four connecting columns are inclined in a first direction to a corresponding radial direction and a second two connecting columns of the at least four connecting columns are inclined in a second direction to a corresponding radial direction, the second direction being opposite to the first direction such that deformation forces acting in the axial direction inside the column bodies of the at least four connecting columns, owing to the relative movement in the corresponding radial direction between the inner armature and the outer armature, have an opposite direction in the first two connecting columns than in the second two connecting columns, so that a relative displacement of the armatures in axial directions is prevented. 
     
     
       11. The elastic joint according to  claim 10 , wherein the deformation forces cancel each other out completely, so that a relative displacement of the armature in the axial direction is prevented. 
     
     
       12. The elastic joint according to  claim 1 , wherein the at least four connecting columns each respectively define an extension direction that is inclined with respect to a corresponding one of the two radial directions, wherein the extension direction for each of the at least four connecting columns is inclined with respect to the respective corresponding radial direction in an acute angle of between 25 degrees and 65 degrees. 
     
     
       13. The elastic joint according to  claim 1 , wherein the at least four connecting columns comprise column bodies, wherein the at least four connecting columns each respectively define an extension direction that is inclined with respect to a corresponding radial direction the, axial direction defines an axis, and wherein the at least four connecting columns respectively define a center axis that defines the extension direction, wherein all center axes meet each other essentially in a common area located substantially on the axis of the axial direction. 
     
     
       14. The elastic joint according to  claim 1 , wherein the at least four connecting columns comprise column bodies, wherein a cross-section area of each column body increases along the column body from a center of the column body towards the inner armature and the outer armature. 
     
     
       15. The elastic joint according to  claim 1 , wherein the at least four connecting columns comprise column bodies, wherein each column body presents an outer surface facing in the axial direction towards the outside of the elastic joint and having a concave shape as seen from the outside. 
     
     
       16. The elastic joint according to  claim 1 , wherein for each of the at least four connecting columns the inner armature and the outer armature form support surfaces diametrically opposed to each other and axially symmetrical, where lines perpendicular to the support surfaces are disposed parallel to an extension direction of the respective connecting column. 
     
     
       17. The elastic joint according to  claim 1 , wherein the outer armature presents a closed housing ring, at the inside of which ring a protrusion is formed respectively for the formation of a support surface. 
     
     
       18. The elastic joint of  claim 17 , wherein the ring and the protrusion are molded out of one plastic piece. 
     
     
       19. The elastic joint according to  claim 1 , wherein the inner armature forms a rod-like basic structure, a center area of the inner armature being formed with a point-symmetrical radial bulge for the formation of support surfaces for the at least four connecting columns, wherein in particular the support surfaces are only formed in a transition area between a base of the bulge and a bulge maximum. 
     
     
       20. The elastic joint of  claim 19 , wherein the point-symmetrical radial bulge is axially symmetrical with respect to a radial center plane. 
     
     
       21. The elastic joint according to  claim 19 , wherein at an inside of the outer armature, at an outside of the inner armature, or a combination thereof, and at the bulge of the inner armature, an elastomeric abutment is provided that extends circularly and in a circumferential direction. 
     
     
       22. The elastic joint according to  claim 1 , wherein the elastic body is configured such that a single vulcanization tool can enter the inside of the elastic body from both sides of the elastic joint. 
     
     
       23. The elastic joint according to  claim 1  wherein the elastomeric body comprises sections realized by recesses that extend completely in the axial direction through the elastic joint wherein the at least four connecting columns are spaced from each other by the recesses. 
     
     
       24. The elastic joint according to  claim 1  wherein the radial stiffness of at least one of the at least four connecting columns is different than the radial stiffness of at least one other one of the at least four connecting columns. 
     
     
       25. The elastic joint according to  claim 1  wherein the difference ratio of an axial stiffness versus the radial stiffness of the elastic joint is above 1.0. 
     
     
       26. The elastic joint according to  claim 25 , wherein the difference ratio of axial stiffness versus radial stiffness of the elastic joint is about 1.4. 
     
     
       27. The elastic joint according to  claim 1  wherein the elastomeric body provides a cardanic stiffness for the elastic joint. 
     
     
       28. An elastic joint for a wheel suspension of a motor vehicle, comprising:
 an inner armature; 
 an outer armature surrounding the inner armature, wherein the inner armature and the outer armature define an axial direction and two radial directions perpendicular to the axial direction as well as perpendicular to each other and disposed in a circumferential plane; 
 an elastomeric body comprising a first portion fixed to the inner armature at an interface such that the inner armature is fixed against rotational movement relative to the elastomeric body at the interface and a second portion fixed to the outer armature for the mutual elastic retention of the inner armature and the outer armature, wherein the elastomeric body includes at least four connecting columns respectively extending from the inner armature to the outer armature, 
 and a hydraulic working chamber delimited by said at least four connecting columns and wherein the at least four connecting columns sectionally delimit the hydraulic working chamber into sections and wherein the hydraulic working chamber comprises a membrane structure that delimits the chamber in an axial direction where no connecting column is formed. 
 
     
     
       29. The elastic joint according to  claim 28  wherein a removable closure element is provided to allow filling of the hydraulic working chambers with a fluid in a pre-installation condition and for sealingly closing of the hydraulic working chamber in an installation condition. 
     
     
       30. An elastic joint for a wheel suspension of a motor vehicle, comprising:
 an inner armature; 
 an outer armature surrounding the inner armature, wherein the inner armature and the outer armature define an axial direction and two radial directions perpendicular to the axial direction as well as perpendicular to each other and disposed in a circumferential plane; 
 and an elastomeric body comprising a first portion fixed to the inner armature at an interface such that the inner armature is fixed against rotational movement relative to the elastomeric body at the interface and a second portion fixed to the outer armature for the mutual elastic retention of the inner armature and the outer armature, wherein the elastomeric body includes at least four connecting columns respectively extending from the inner armature to the outer armature, wherein the at least four connecting columns are elastically deformable in the radial direction to elastically connect the inner armature to the outer armature, wherein the deformation of one of the connecting columns does not affect the deformation behavior of any other of the at least four connecting columns; 
 wherein the elastic joint has a central radial plane that partitions the elastic joint into two essentially equally dimensioned joint sections. 
 
     
     
       31. The elastic joint according to  claim 30 , wherein the difference ratio of an axial stiffness versus a radial stiffness of the elastic joint is above 1.0. 
     
     
       32. The elastic joint according to  claim 31 , wherein the difference ratio of the axial stiffness versus the radial stiffness of the elastic joint is realized by about 1.4. 
     
     
       33. The elastic joint according to  claim 30  wherein the elastomeric body provides a cardanic stiffness for the elastic joint. 
     
     
       34. An elastic joint for a wheel suspension of a motor vehicle, comprising:
 an inner armature; 
 an outer armature surrounding the inner armature, wherein the armatures define an axial direction and two radial directions perpendicular to the axial direction as well as perpendicular to each other and disposed in a circumferential plane; and 
 an elastomeric body comprising a first portion fixed to the inner armature at an interface such that the inner armature is fixed against rotational movement relative to the elastomeric body at the interface and a second portion fixed to the outer armature for the mutual elastic retention of the inner armature and the outer armature, wherein the elastomeric body includes at least four connecting columns respectively extending from the inner armature to the outer armature wherein the at least four connecting columns are elastically deformable in the radial direction to elastically connect the inner armature to the outer armature and are spaced from one another along the elastomeric body such that the deformation of one of the at least four a connecting columns does not affect the deformation behavior of any other one of the at least four connecting columns.